Continuous wave-transmission system



. Jan, 1:5, 1925; 1,523,011

-w. 1 GARITY CONTINUOUS WAVE TRANSMISSION SYSTEM Filed Sept. 23, 1920 v i r n wa WILLIAM n GAB-ITY, or -nnw Yomr, n.

Y.,' assrenon TO DE FOREST RADIO TELE- PHONE a TELEGRAPH COMPANY, OF NEW. YonK, n. Y., A CORPORATION OF DELA- WARE.

CONTINUOUS .WAVE-TRANSMISSION SYSTEM.

Application filed September 23, 1920. Serial No. 412,322.

To all whom/it. concern:v

Be it known that 1, WILLIAM E. GARITY,

a citizen of the United States, residing, in New York,in the county of Kings and State or more oscillions and wherein parasitic oscillations are suppressed, and particularly such Oscillations which are harmonics of the main or fundamental frequency. f

A furthenobject, therefore, is to provide a transmission system which is more eflicient in its operation than those heretofore em ployed.

Further objects of the invention will appear morefully hereinafter.

The invention consists substantially in the construction, combination, locatlon and relative arrangement of Parts in the circuit arev Suitable source for example: b

rangements employed, all as will be more fullyhereinafter set forth, as shown by the accompanying. drawing and finally pointed out'in the appended claims. I

In the drawing the .figure illustrates a circuit arrangement embodying my invention. 7

Present continuous wave transmitters of the arc type are very objectionable because of the relatively large percentage of total radiated energy represented in parasitic oscillations which usually are of frequencies which are harmonics of the'main or fundafar lBSS'lIl number and of relatively small energy compared with that in the fundamental frequency. The existence Of such parasitic harmonics, even in continuous wave transmitters of theoscillion type, is objectionable, 'a detriment, and decreases the efficiency of thesystein. It is towards meth F ods and circuits for suppressing such harmonies in a transmitting system of the oscillation type that my present invention is directed. In the drawing I liave shown one s mple type-of oscillation transmitting system to which, of course, I do not desire to be limited, orrestricted, as the particular transmltting circuit selected has been selected merely for the purpose of illustrating the principles of my invention as applied thereto, and it will be obvious that my-invention may equally well be applied to any 1 transmitting circuit. In the illustration selected, however, the antenna 1 is connected I to the earth 2 through the usual inductance '3 and capacity fl; One end of the inductance is connected to the grid electrode 5 of the oscillion tube 6, the plate electrode 7 of which is adjustably connected to the opposite. end of the inductance. The filament electrode 8 of the oscillion 6 is lighted in 'the usual well known manner from any means of -a battery. The B current in t 0 form selected for illustration is supplied from a D. C: generator 10 which in this instance is connected to opposite sides of the capacity 4. In accordance with my invention I in sert in the lead between the oscillating circuit 1, 3, 4: 2, and one of the electrodes of the oscillion a branch or rejector circuit, the natural period of which is tuned to the frequency of the harmonic which it is desiredto suppress. Such branch circuit consists of a capacity 10 and an inductance 11 connected in series with each other but in parallel with the-electrode lead in which the rejector circuit is included. For example, in the principle of the invention, if the inductancell and 'the capacity 10 of the re- 'j'ector circuitbe such that 2n- /G ',L equals the period of the objectionableharmonic, this rejector circuit will offer an infinite impedance to impulses of this frequency (provided the resistance, dielectric and radiation'losses from this rejector circuit be neglected). Secondly, no harmonic impulse-of this frequency can reach the electrode of the oscillion in the lead of which the rejector circuit is inserted, to thereby cause the tube or oscillion 6 to oscillate at the said objectionable frequency. Similar 1y, if there are two harmful harmonics which otherwi and grid electrodes,

circuits may 1 frequency to be.

it is desired to suppress, a second'rejector circuit can be inserted in the lead ofthe electrode as desired. It will be apparent "I claim as new and useful and of my own invention and desire to secure by Letters Patent is 1. Ina radio transmitting system, and in combination with a source of undamped oscillations including a vessel having associated therewith a hot electrode and a plurality of cold electrodes, and circuits therefor, of a plurality of rejector circuits each tuned to a frequency to be suppressed, and included in the circuit of each cold electrode.

2. In a radio transmitting system and in combination with a source of undamped oscillations including a vessel having asso ciated therewitha hot electrode, and plate and grid electrodes, and circuits for said electrodes, of a rejector circuit tuned to the suppressed included in the grid-filament circuit, said rejector circuit 'senot affecting the oscillations produced.

' 3. In a radio transmitting system and in combination with a source of undamped oscillations including a vessel having associated therewith a hot electrode, and plate cuits each tuned to a frequency to be suppressed aud included in the circuit of said grid electrode.

4. In a radio transmitting system and in combination with a source of undamped oscillations including a vessel having associated therewith a hot electrode, and plate and grid electrodes, and circuits for said electrodes,of a-plurality of rejector circuits each tuned to a frequencyto be suppressed and included in the circuits of said grid and plate electrodes, said rejector circuits electrodes, and circuits for said of a plurality of rejector'. c1r-' otherwise not afiecting the oscillations pro duced. I

5. In a radio transmitting system, and in combination with a source of undamped oscillations including a vessel having associated therewith a hot electrode and a plurality of cold electrodes,- and circuits there for, and means for suppressing parasitic oscillations consistin of a circuit comprising an inductance and capacity connected 1n 'serieswith each other and included in the circuit of each cold electrode said suppressing c1rcu1t otherwise not affecting the oscillations produced.

6. In a radio transmitting system, and in combination with a source of undamped os-' clllations includlng a vessel having associated therewith a hot electrode and a plurality of cold electrodes, and circuits there for, and means for suppressingparasitic oscillations consisting of a plurality of circuits each'comprising an inductance and a capacity in series, included in the circuit of each cold electrode, said suppressing circuit otherwise not affecting the oscillations produced. p 7

7 In a radio transmitting system, and in combination with a source of undamped 05- I cillations including a vessel having associated therewith a hot electrode, and plate and grid electrodes-and circuits for said electrodes, and means for suppressing parasitic oscillations consisting of a circuit comprising an inductance and capacity connected in series with each other and included in the grid-filament circuit, said suppressing circuit otherwise not affecting the oscillationsproduced.

8. In a radio transmitting. system and in combination with a source of undamped oscillations including a vessel having associated therewith a hot electrode, and plate Y and grid electrodes, and circuits for said electrodes, and means for suppressing .parasitic oscillations consisting of a plurality of circuits each comprising an inductance and? a capacity in series, included in the circuit of said grid electrode, said suppressing'cin cuit otherwise not affecting the oscillations produced. I 4

In testimony whereof I have hereunto set my hand on this 20th day of September A. 1)., 1920. a

WILLIAM E. GARITY. 

